RESUMO
The mechanisms of cellular energy sensing and AMPK-mediated mTORC1 inhibition are not fully delineated. Here, we discover that RIPK1 promotes mTORC1 inhibition during energetic stress. RIPK1 is involved in mediating the interaction between AMPK and TSC2 and facilitate TSC2 phosphorylation at Ser1387. RIPK1 loss results in a high basal mTORC1 activity that drives defective lysosomes in cells and mice, leading to accumulation of RIPK3 and CASP8 and sensitization to cell death. RIPK1-deficient cells are unable to cope with energetic stress and are vulnerable to low glucose levels and metformin. Inhibition of mTORC1 rescues the lysosomal defects and vulnerability to energetic stress and prolongs the survival of RIPK1-deficient neonatal mice. Thus, RIPK1 plays an important role in the cellular response to low energy levels and mediates AMPK-mTORC1 signaling. These findings shed light on the regulation of mTORC1 during energetic stress and unveil a point of crosstalk between pro-survival and pro-death pathways.
Assuntos
Proteína 5 Relacionada à Autofagia/genética , Proteína de Domínio de Morte Associada a Fas/genética , Intestino Grosso/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Proteína Serina-Treonina Quinases de Interação com Receptores/genética , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Animais Recém-Nascidos , Proteína 5 Relacionada à Autofagia/deficiência , Caspase 8/genética , Caspase 8/metabolismo , Morte Celular/genética , Proteína de Domínio de Morte Associada a Fas/deficiência , Regulação da Expressão Gênica , Glucose/antagonistas & inibidores , Glucose/farmacologia , Células HEK293 , Células HT29 , Humanos , Intestino Grosso/efeitos dos fármacos , Intestino Grosso/patologia , Células Jurkat , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Lisossomos/patologia , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Metformina/antagonistas & inibidores , Metformina/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosforilação , Proteína Serina-Treonina Quinases de Interação com Receptores/deficiência , Transdução de Sinais , Sirolimo/farmacologia , Proteína 2 do Complexo Esclerose Tuberosa/genética , Proteína 2 do Complexo Esclerose Tuberosa/metabolismoRESUMO
Autophagy is vital for maintaining cellular homeostasis through removing impaired organelles. It has recently been found to play pivotal roles in diabetes mellitus (DM), which is associated with increased bone fracture risk and loss of bone density. However, the mechanism whereby autophagy modulates DM-induced bone loss is not fully elucidated. Previous work has shown that 1α,25-Dihydroxyvitamin D3 (1,25D) exerts positive effects on autophagy, thus affecting bone metabolism. Here, we investigated whether autophagy was involved in the regulation of diabetic bone metabolism. Using Micro-CT, Elisa, histology, and histomorphometry analysis, we demonstrated that 1,25D rescues glucose metabolism dysfunction and ameliorates bone loss in diabetic mice. In vitro, 1,25D alleviated primary osteoblast dysfunction and intracellular oxidative stress through reducing prolonged high-glucose-mediated excessive autophagy in primary osteoblasts, reflected by decreased protein level of Beclin1 and LC3. Of note, the autophagy activator rapamycin (RAP) ablated the positive effects of 1,25D in diabetic environment, leading to a marked increase in autolysosomes and autophagosomes, examined by mRFP-GFP-LC3 fluorescence double labeling. The excessive autophagy induced by high glucose was deleterious to proliferation and differentiation of primary osteoblasts. Additionally, biochemical studies identified that PI3K/Akt signaling could be activated by 1,25D, resulting in the inhibition of FoxO1. We confirmed that FoxO1 deficiency alleviated high-glucose-induced autophagy and improved biological functions of primary osteoblasts. Together, our results suggest that the PI3K/Akt/FoxO1 signaling pathway is involved in the osteoprotective effect of 1,25D by attenuating autophagy in diabetes, providing a novel insight for the prevention and treatment of diabetes-caused bone loss.
Assuntos
Autofagia/efeitos dos fármacos , Calcitriol/farmacologia , Diabetes Mellitus Experimental/tratamento farmacológico , Proteína Forkhead Box O1/genética , Glucose/metabolismo , Osteoporose/tratamento farmacológico , Animais , Autofagossomos/efeitos dos fármacos , Autofagossomos/metabolismo , Autofagia/genética , Proteína Beclina-1/genética , Proteína Beclina-1/metabolismo , Densidade Óssea/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/patologia , Fêmur/efeitos dos fármacos , Fêmur/metabolismo , Fêmur/patologia , Proteína Forkhead Box O1/deficiência , Regulação da Expressão Gênica , Glucose/antagonistas & inibidores , Glucose/farmacologia , Lisossomos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Transgênicos , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Osteoblastos/patologia , Osteoporose/induzido quimicamente , Osteoporose/genética , Osteoporose/patologia , Estresse Oxidativo , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Sirolimo/farmacologia , Estreptozocina , Resultado do TratamentoRESUMO
Diabetic nephropathy (DN) is one of the severe microvascular complications of diabetes mellitus. Oxidative stress resulting from aberrant metabolism of glucose mediates renal inflammation and fibrosis in the progression of DN. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor regulating the expression of antioxidant enzymes. Activating Nrf2 will give a promising therapy for DN. To discover novel Nrf2 activators, we have investigated caffeoylisocitric acid using mesangial cells under high glucose. The results showed at 10 µM, caffeoylisocitric acid significantly inhibited the self-limited proliferation of mesangial cells induced by high glucose. Further assessments have disclosed caffeoylisocitric acid mitigated oxidative stress, inflammation and accumulation of extracellular matrix resulting from high glucose via inactivating MAPK signalling. Meanwhile activation of Nrf2 was observed and involved in these effects through the interaction between Keap1 and caffeoylisocitric acid to disrupt Keap1-Nrf2 complex. Therefore, caffeoylisocitric acid is a promising Nrf2 activator targeting DN.
Assuntos
Ácidos Cafeicos/farmacologia , Nefropatias Diabéticas/tratamento farmacológico , Descoberta de Drogas , Glucose/antagonistas & inibidores , Hipoglicemiantes/farmacologia , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Células Mesangiais/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/metabolismo , Ácidos Cafeicos/química , Células Cultivadas , Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/patologia , Relação Dose-Resposta a Droga , Matriz Extracelular/efeitos dos fármacos , Glucose/metabolismo , Humanos , Hipoglicemiantes/química , Células Mesangiais/metabolismo , Estrutura Molecular , Estresse Oxidativo/efeitos dos fármacos , Relação Estrutura-AtividadeRESUMO
Synthetic polymers prepared using several functional monomers have attracted attention as cost-effective protein affinity reagents and alternative to antibodies. We previously reported the synthesis of poly NIPAm-based nanoparticles (NPs) using several functional monomers that can capture target molecules. In this study, we designed NPs for capturing glucose and inhibiting intestinal absorption in living mice. For capturing glucose, we focused on the Maillard reaction between primary amines and aldehyde residues. We hypothesized that the primary amine-containing NPs can capture the open-chain structure of glucose via the Maillard reaction and inhibit intestinal absorption. NPs were prepared by the precipitation polymerization of NIPAm, N-tert-butylacrylamide (TBAm), trifluoroacetate-protected N-(3-aminopropyl)methacrylamide (T-APM), and N,N'-methylenebisacrylamide. Then, T-APM in NPs was deprotected by NH3 (aq). The amount of glucose captured by NPs depended on the percentage of TBAm and APM in vitro. After 24 h, only 2% of orally administered NPs remained in the body after administration, suggesting that many NPs were excreted without being absorbed. The prepared NPs significantly inhibited an increase in blood glucose concentration after the oral administration of glucose and NPs, indicating that NPs capture glucose and inhibit intestinal absorption. These results show the potential of using synthetic polymer nanoparticles for inhibiting postprandial hyperglycemia.
Assuntos
Acrilamidas/química , Glucose/metabolismo , Absorção Intestinal/efeitos dos fármacos , Nanopartículas/administração & dosagem , Nanopartículas/química , Polímeros/química , Administração Oral , Animais , Glucose/antagonistas & inibidores , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Distribuição TecidualRESUMO
Triazole fungicides are widely used in agriculture that leads to pollution of freshwater ecosystems. The mechanisms of toxicity to fish by the triazole fungicide Topas that contains penconazole (1-[2-(2,4-dichlorophenyl)pentyl]-1H-1,2,4-triazole) have not been studied. The present study aimed to evaluate the effect of goldfish exposure for 96 h to the fungicide Topas at concentrations of 1.5, 15, or 25 mg/L on the plasma and liver biochemical parameters and blood hematological profile. Goldfish exposure to Topas decreased alanine and aspartate transaminase activity and increased lactate dehydrogenase activity in the liver. Plasma lactate dehydrogenase and alanine transaminase activities were elevated in fungicide-treated fish. Topas exposure also enhanced plasma glucose and triacylglycerol concentrations. In the liver, fungicide treatment decreased levels of glucose but elevated triacylglycerols, glycogen, and protein. The results indicate that acute exposure of goldfish to Topas induced strong metabolic perturbations and disruptions of metabolic parameters, suggesting that these could be used to assess sublethal or acute toxic effects of pesticides on aquatic species.
Assuntos
Fungicidas Industriais/toxicidade , Glucose/antagonistas & inibidores , Fígado/efeitos dos fármacos , Triazóis/toxicidade , Animais , Relação Dose-Resposta a Droga , Fungicidas Industriais/administração & dosagem , Fungicidas Industriais/química , Glucose/metabolismo , Carpa Dourada , Fígado/metabolismo , Estrutura Molecular , Triazóis/administração & dosagem , Triazóis/químicaRESUMO
Diabetic nephropathy (DN) is the major cause of kidney related diseases in patients induced by high glucose (HG) affecting around 40% of type 1 and 2 diabetic patients. It is characterized by excessive inflammation inducing factors, reactive oxygen species (ROS) overproduction, and potential epigenomic related changes. Fucoxanthin (FX), a carotenoid found in brown seaweed, has a structure which includes an allenic bond and a 5,6-monoepoxide in the molecule, with strong antioxidant and anti-inflammatory activity. However, understanding of the impact of FX on DN was lacking. In this study we tested the early effects of high glucose (HG) on mouse mesangial kidney Mes13 cells, a potential in vitro cell culture model of DN. Our results show that HG induced oxidative stress on kidney mesangial Mes13 cells, while FX treatment attenuates the oxidative stress by decreasing the ROS, demonstrated by flow cytometry. Next, we utilized next-generation sequencing (NGS) to profile the HG-induced early epigenomic and transcriptomic changes in this in vitro DN model and the protective effects of FX. Differentially expressed genes (DEGs) and differentially methylated regions (DMRs) were analyzed using R software in HG and FX treated groups. Differential regulation of signaling pathways was studied using Reactome Pathway Analysis in the comparison. DEG analysis shows that novel biomarkers with specific pathways, including interleukin regulation, Toll-like receptor pathway, and PKA phosphorylation pathways, were found to be modulated by the FX treatment. TGF ß 1i1 (TGFB 1i1), MAP-3-kinase-13(MAP3K13) involved in crucial cellular processes including glucose metabolism, phosphodiesterase regulation was methylated in HG, which was demethylated with FX treatment. Integrated transcriptomic and CpG methylome analysis of DEGs and DMRs revealed that genes like adenylate cyclase (Adcy7), calponin 1 (CNN1), potassium voltage-gated channel interacting protein 2 (KCNIP2), phosphatidylinositol-4-phosphate 5-kinase type 1 ß (PIP5K1B), and transmembrane protein with EGF-like and two follistatin-like domains 1 (TMEFF1), which were modulated by FX in HG-exposed Mes13 cells, potentially modulate ion channel transport and glucose metabolism. In summary, our current study shows that novel early epigenomic and transcriptomic biomarkers were altered during the disease progression of HG-induced DN and that FX modified these alterations potentially contributing to the protective effects of mesangial cells from the HG-induced oxidative stress and damage.
Assuntos
Carotenoides/farmacologia , Glucose/antagonistas & inibidores , Rim/efeitos dos fármacos , Células Mesangiais/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Xantofilas/farmacologia , Animais , Carotenoides/química , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Epigênese Genética/efeitos dos fármacos , Epigênese Genética/genética , Glucose/metabolismo , Rim/metabolismo , Células Mesangiais/metabolismo , Camundongos , Estrutura Molecular , Estresse Oxidativo/efeitos dos fármacos , Substâncias Protetoras/química , Espécies Reativas de Oxigênio/análise , Transcriptoma , Xantofilas/químicaRESUMO
Previously, we isolated six heterocyclic compounds (1-6) from the fruits of mulberry trees (Morus alba L.) and determined that loliolide affords rat pancreatic islet ß-cell (INS-1) protection against streptozotocininduced cytotoxicity. In the present study, we further investigated the effect of the six heterocyclic compounds (1-6) on glucose-stimulated insulin secretion (GSIS) in INS-1 cells. Among them, (R)5hydroxypyrrolidin2one(1) and indole (6) increased GSIS without inducing cytotoxicity. Additionally, compounds 1 and 6 enhanced the phosphorylation of total insulin receptor substrate-2, phosphatidylinositol 3-kinase, and Akt, and activated pancreatic and duodenal homeobox-1, which play a crucial role in ß-cell functions related to insulin secretion. Collectively, these findings indicate that (R)5hydroxypyrrolidin2one(1) and indole (6), isolated from M. alba fruits, may be beneficial in managing type 2 diabetes.
Assuntos
Glucose/antagonistas & inibidores , Compostos Heterocíclicos/farmacologia , Hipoglicemiantes/farmacologia , Secreção de Insulina/efeitos dos fármacos , Animais , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Glucose/farmacologia , Compostos Heterocíclicos/química , Hipoglicemiantes/química , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Estrutura Molecular , Ratos , Relação Estrutura-AtividadeRESUMO
Diabetes, a metabolic disorder, is caused by a high blood sugar level. Diabetes is an increasing health issue and search for potent antidiabetic agents is desirable. Owing to its ethnomedicinal value, the Himalayan perennial herb Bergenia stracheyi (Hook. f. & Thoms.) Engl. (Saxifragaceae Juss) is used to treat diabetes. Herein, an efficient high-speed countercurrent chromatography with elution mode is reported for separation of active compounds from B. stracheyi. In current investigation, six main compounds including ß-arbutin (1), bergenin (2), 6-O-galloylarbutin (3), gallic acid (4), 11-O-galloylbergenin (5), and (-)-epicatechin 3-O-gallate (6) with above 95% purity were efficiently separated in a single run using biphasic tert-butyl methyl ether/n-butanol/methanol/water (1:3:1:5, v/v/v/v) solvent system. The structures of these compounds were characterized using spectral techniques and compared with the literature. Antidiabetic and antioxidant activities evaluation of the study samples showed that ß-arbutin (1) and 6-O-galloylarbutin (3) have a significant protective effect, especially at high dose against hydrogen peroxide induced oxidative injury. Our results might help further in-depth phytochemical and biological evaluation studies in search of potent antidiabetic compounds from B. stracheyi.
Assuntos
Antioxidantes/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Glucose/antagonistas & inibidores , Hipoglicemiantes/farmacologia , Saxifragaceae/química , Antioxidantes/química , Antioxidantes/isolamento & purificação , Sobrevivência Celular/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Distribuição Contracorrente , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/isolamento & purificação , Glucose/análise , Glucose/metabolismo , Células Hep G2 , Humanos , Peróxido de Hidrogênio/antagonistas & inibidores , Peróxido de Hidrogênio/farmacologia , Hipoglicemiantes/química , Hipoglicemiantes/isolamento & purificação , Estrutura Molecular , Estresse Oxidativo/efeitos dos fármacosRESUMO
Fucoidans are complex polysaccharides derived from brown seaweeds which consist of considerable proportions of L-fucose and other monosaccharides, and sulphated ester residues. The search for novel and natural bioproduct drugs (due to toxicity issues associated with chemotherapeutics) has led to the extensive study of fucoidan due to reports of it having several bioactive characteristics. Among other fucoidan bioactivities, antidiabetic and anticancer properties have received the most research attention in the past decade. However, the elucidation of the fucoidan structure and its biological activity is still vague. In addition, research has suggested that there is a link between diabetes and cancer; however, limited data exist where dual chemotherapeutic efforts are elucidated. This review provides an overview of glucose metabolism, which is the central process involved in the progression of both diseases. We also highlight potential therapeutic targets and show the relevance of fucoidan and its derivatives as a candidate for both cancer and diabetes therapy.
Assuntos
Antineoplásicos/química , Diabetes Mellitus/metabolismo , Glucose/metabolismo , Hipoglicemiantes/química , Neoplasias/metabolismo , Polissacarídeos/química , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Diabetes Mellitus/tratamento farmacológico , Glucose/antagonistas & inibidores , Humanos , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Neoplasias/tratamento farmacológico , Polissacarídeos/farmacologia , Polissacarídeos/uso terapêuticoRESUMO
Two enantiomeric humulane sesquiterpenes, namely (+)-alashanoid N (1a) and (-)-alashanoid N (1b), along with two known analogs ((2R,3R,5R)-2,3-epoxy-6,9-humuladien-5-ol-8-one (2) and (2R,3S,5R)-2,3-epoxy-6,9-humuladien-5-ol-8-one (3)), were described from the peeled stems of a folk Mongolian herbal medicine Syringa pinnatifolia. Their structures were characterized based on UV, IR, NMR, and HR-ESI-MS data analyses, and the absolute configurations were determined by data analysis of X-ray diffraction and quantum chemical calculations. (+/-)-Alashanoid N showed inhibition against NO production in RAW 264.7 macrophage cells with IC50 values of 90.1â µM and 71.7â µM, and protective effect against oxygen-glucose deprivation injury to H9c2 cells at a concentration of 20â µM and 5â µM, respectively.
Assuntos
Substâncias Protetoras/farmacologia , Syringa/química , Animais , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Glucose/antagonistas & inibidores , Glucose/metabolismo , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Camundongos , Conformação Molecular , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/biossíntese , Oxigênio/metabolismo , Substâncias Protetoras/química , Substâncias Protetoras/isolamento & purificação , Células RAW 264.7 , Ratos , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
Gymnema sylvestre (Retz.) Schult is a multi-purpose traditional medicine that has long been used for the treatment of various diseases. To discover the potential bioactive composition of G. sylvestre, a chemical investigation was thus performed. In this research, four new C21 steroidal glycosides sylvepregosides A-D (1-4) were isolated along with four known compounds, gymnepregoside H (5), deacetylkidjoladinin (6), gymnepregoside G (7) and gymnepregoside I (8), from the ethyl acetate fraction of G. sylvestre. The structures of the new compounds were established by extensive 1D and 2D nuclear magnetic resonance (NMR) spectra with mass spectroscopy data. Compounds 1-6 promoted glucose uptake by the range of 1.10- to 2.37-fold, respectively. Compound 1 showed the most potent glucose uptake, with 1.37-fold enhancement. Further study showed that compounds 1 and 5 could promote GLUT-4 fusion with the plasma membrane in L6 cells. The result attained in this study indicated that the separation and characterization of these compounds play an important role in the research and development of new anti-diabetic drugs and pharmaceutical industry.
Assuntos
Glucose/antagonistas & inibidores , Glicosídeos/farmacologia , Gymnema sylvestre/química , Hipoglicemiantes/farmacologia , Esteroides/farmacologia , Animais , Linhagem Celular , Indústria Farmacêutica , Glucose/metabolismo , Glicosídeos/química , Glicosídeos/isolamento & purificação , Hipoglicemiantes/química , Hipoglicemiantes/isolamento & purificação , Conformação Molecular , Ratos , Estereoisomerismo , Esteroides/química , Esteroides/isolamento & purificaçãoRESUMO
This study investigated the effects of Tiliacora triandra (Colebr.) Diels aqueous extract (TTE) on hepatic glucose production in hepatocellular carcinoma (HepG2) cells and type 2 diabetic (T2DM) conditions. HepG2 cells were pretreated with TTE and its major constituents found in TTE, epicatechin (EC) and quercetin (QC). The hepatic glucose production was determined. The in vitro data were confirmed in T2DM rats, which were supplemented daily with 1000 mg/kg body weight (BW) TTE, 30 mg/kg BW metformin or TTE combined with metformin for 12 weeks. Results demonstrate that TTE induced copper-zinc superoxide dismutase, glutathione peroxidase and catalase genes, similarly to EC and QC. TTE decreased hepatic glucose production by downregulating phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) and increasing protein kinase B and AMP-activated protein kinase phosphorylation in HepG2 cells. These results correlated with the antihyperglycemic, antitriglyceridemic, anti-insulin resistance, and antioxidant activities of TTE in T2DM rats, similar to the metformin and combination treatments. Consistently, impairment of hepatic gluconeogenesis in T2DM rats was restored after single and combined treatments by reducing PEPCK and G6Pase genes. Collectively, TTE could potentially be developed as a nutraceutical product to prevent glucose overproduction in patients with obesity, insulin resistance, and diabetes who are being treated with antidiabetic drugs.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Glucose/antagonistas & inibidores , Hipoglicemiantes/farmacologia , Menispermaceae/química , Extratos Vegetais/farmacologia , Animais , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/induzido quimicamente , Diabetes Mellitus Tipo 2/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais , Glucose/biossíntese , Células Hep G2 , Humanos , Hipoglicemiantes/química , Hipoglicemiantes/isolamento & purificação , Injeções Intraperitoneais , Masculino , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/metabolismo , Estreptozocina/administração & dosagem , Células Tumorais Cultivadas , Água/químicaRESUMO
Glucose addiction is observed in cancer and other diseases that are associated with hyperproliferation. The development of compounds that restrict glucose supply and decrease glycolysis has great potential for the development of new therapeutic approaches. Addressing facilitative glucose transporters (GLUTs), which are often upregulated in glucose-dependent cells, is therefore of particular interest. This article reviews a selection of potent, isoform-selective GLUT inhibitors and their biological characterization. Potential therapeutic applications of GLUT inhibitors in oncology and other diseases that are linked to glucose addiction are discussed.
Assuntos
Transportador de Glucose Tipo 1/antagonistas & inibidores , Transportador de Glucose Tipo 2/antagonistas & inibidores , Transportador de Glucose Tipo 3/antagonistas & inibidores , Transportador de Glucose Tipo 4/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/farmacologia , Glucose/antagonistas & inibidores , Glucose/metabolismo , Transportador de Glucose Tipo 1/química , Transportador de Glucose Tipo 2/química , Transportador de Glucose Tipo 3/química , Transportador de Glucose Tipo 4/química , Humanos , Modelos Moleculares , Estrutura Molecular , Bibliotecas de Moléculas Pequenas/químicaRESUMO
Swelling of secretory vesicles is critical for the regulated release of intra-vesicular contents from cells during secretion. At the secretory vesicle membrane of the exocrine pancreas and neurons, GTP-binding G proteins, vH+-ATPase, potassium channels and AQP water channels, are among the players implicated in vesicle volume regulation. Here we report in the endocrine insulin-secreting MIN6 cells, the similar requirement of vH+-ATPase-mediated intracellular acidification on glucose-stimulated insulin release. MIN6 cells exposed to the vH+-ATPase inhibitor Bafilomycin A show decreased acidification of the cytosolic compartment that include insulin-carrying granules. Additionally, a loss of insulin granules near the cell plasma membrane following Bafilomycin A treatment, suggests impaired transport of insulin granules and consequent decrease in glucose-stimulated insulin secretion and accumulation of intracellular insulin. These results suggest that vH+-ATPase-mediated intracellular acidification is required for insulin secretion in beta cells.
Assuntos
Adenosina Trifosfatases/metabolismo , Glucose/metabolismo , Secreção de Insulina , Células Secretoras de Insulina/metabolismo , Adenosina Trifosfatases/antagonistas & inibidores , Animais , Células Cultivadas , Glucose/antagonistas & inibidores , Secreção de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/efeitos dos fármacos , Macrolídeos/farmacologia , CamundongosRESUMO
Diabetic nephropathy (DN) is a severe microvascular complication of diabetes mellitus. Oxidative stress and fibrosis largely contribute to the progression of DN. Recently, Nrf2 was found to be a potential target preventing DN. In the discovery of novel Nrf2 activators for the treatment of DN, we have evaluated coumarin derivatives from Wikstroemi indiaca. Molecular docking results have shown compound 4 could bind to Keap1 and activate Nrf2 significantly. Cell-based assays have revealed compound 4 activated Nrf2 and attenuated oxidative stress and fibrosis induced by high glucose in mesangial cells. Meanwhile, it was validated that disruption of the interaction between Keap1 and Nrf2 was involved in the activation of Nrf2 by compound 4 in mesangial cells under high glucose.
Assuntos
Cumarínicos/farmacologia , Descoberta de Drogas , Fibrose/tratamento farmacológico , Glucose/antagonistas & inibidores , Células Mesangiais/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/metabolismo , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cumarínicos/síntese química , Cumarínicos/química , Nefropatias Diabéticas/tratamento farmacológico , Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/patologia , Relação Dose-Resposta a Droga , Fibrose/metabolismo , Fibrose/patologia , Glucose/farmacologia , Humanos , Células Mesangiais/metabolismo , Células Mesangiais/patologia , Simulação de Acoplamento Molecular , Estrutura Molecular , Estresse Oxidativo/efeitos dos fármacos , Relação Estrutura-AtividadeRESUMO
Mitochondrial dysfunction plays a crucial role in the central pathogenesis of insulin resistance and type 2 diabetes mellitus. Macrophages play important roles in the pathogenesis of insulin resistance. Lauric acid is a 12-carbon medium chain fatty acid (MCFA) found abundantly in coconut oil or palm kernel oil and it comes with multiple beneficial effects. This research objective was to uncover the effects of the lauric acid on glucose uptake, mitochondrial function and mitochondrial biogenesis in insulin-resistant macrophages. THP-1 monocytes were differentiated into macrophages and induce insulin resistance, before they were treated with increasing doses of lauric acid (5 µM, 10 µM, 20 µM, and 50 µM). Glucose uptake assay, cellular ROS and ATP production assays, mitochondrial content and membrane potential assay were carried out to analyse the effects of lauric acid on insulin resistance and mitochondrial biogenesis in the macrophages. Quantitative RT-PCR (qRT-PCR) and western blot analysis were also performed to determine the expression of the key regulators. Insulin-resistant macrophages showed lower glucose uptake, GLUT-1 and GLUT-3 expression, and increased hallmarks of mitochondrial dysfunction. Interestingly, lauric acid treatment upregulated glucose uptake, GLUT-1 and GLUT-3 expressions. The treatment also restored the mitochondrial biogenesis in the insulin-resistant macrophages by improving ATP production, oxygen consumption, mitochondrial content and potential, while it promoted the expression of mitochondrial biogenesis regulator genes such as TFAM, PGC-1α and PPAR-γ. We show here that lauric acid has the potential to improve insulin sensitivity and mitochondrial dysregulation in insulin-resistant macrophages.
Assuntos
Glucose/antagonistas & inibidores , Hipoglicemiantes/farmacologia , Ácidos Láuricos/farmacologia , Macrófagos/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Trifosfato de Adenosina/biossíntese , Transporte Biológico/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Relação Dose-Resposta a Droga , Regulação da Expressão Gênica/efeitos dos fármacos , Glucose/metabolismo , Transportador de Glucose Tipo 1/genética , Transportador de Glucose Tipo 1/metabolismo , Transportador de Glucose Tipo 3/genética , Transportador de Glucose Tipo 3/metabolismo , Humanos , Resistência à Insulina , Macrófagos/citologia , Macrófagos/metabolismo , Mitocôndrias/genética , Mitocôndrias/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Biogênese de Organelas , PPAR gama/genética , PPAR gama/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Espécies Reativas de Oxigênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo , Células THP-1 , Acetato de Tetradecanoilforbol/farmacologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
In high fat diet-induced obese mice, the flavonoid derivative of tiliroside, Fla-CN, has antihyperglycemic effects, can improve insulin sensitivity, ameliorate metabolic lipid disorders, and benefits certain disorders characterized by insulin resistance. Fla-CN is a novel lead compound to discovery anti-diabetic and anti-obesity drugs. The present study reported the optimization of Fla-CN to obtain a new derivative, 10b, which has improved glucose consumption at the nanomolar level (EC50 = 0.3 nM) in insulin resistant (IR) HepG2 cells. 10b also increased the glycogen content and glucose uptake, and concurrently inhibited gluconeogenesis in HepG2 cells. Western blotting showed that 10b markedly enhanced the phosphorylation of AMPK (AMP-activated protein kinase) and AS160 (protein kinase B substrate of 160 kDa) and reduced the levels of the gluconeogenesis key enzymes PEPCK (phosphoenolpyruvate carboxykinase) and G6P (glucose 6-phosphatase) in HepG2 cells. The potential molecular mechanism of 10b may be activation of the AMPK/AS160 and AMPK/PEPCK/G6P pathways. We concluded that 10b might be a valuable candidate to discover anti-diabetic drugs.
Assuntos
Flavonoides/farmacologia , Glucose/antagonistas & inibidores , Hipoglicemiantes/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Flavonoides/síntese química , Flavonoides/química , Gluconeogênese/efeitos dos fármacos , Glucose/biossíntese , Células Hep G2 , Humanos , Hipoglicemiantes/síntese química , Hipoglicemiantes/química , Estrutura Molecular , Relação Estrutura-Atividade , Células Tumorais CultivadasRESUMO
Proximal renal tubular damage is a critical process underlying diabetic kidney disease (DKD). Our previous study shows that prostaglandin E1 (PGE1) reduces the apoptosis of renal tubular cells in DKD rats. But its underlying mechanisms remain unclear. In this study we investigated the protective effects of PGE1 in DKD rats and high glucose (HG, 30 mM)-treated HK-2 proximal tubular cells. Four weeks after uninephrectomized streptozotocin-induced diabetic rats were established, the DKD rats were administered PGE1 (10 µg· kg-1· d-1, iv.) for 10 consecutive days. We showed that PGE1 administration did not change blood glucose levels, but alleviated diabetic kidney injury in the DKD rats, evidenced by markedly reduced proteinuria and renal tubular apoptosis. In the in vitro experiments, PGE1 (0.1-100 µM) significantly enhanced HG-reduced HK-2 cell viability. In HG-treated HK-2 cells, PGE1 (10 µM) significantly suppressed the c-Jun N-terminal kinase (JNK) and the mitochondrial apoptosis-related protein expressions such as Bim, Bax, caspase-3 and cleaved caspase-3; similar changes were also observed in the kidney of PGE1-treated DKD rats. By using two pharmacological tools-JNK activator anisomycin (AM) and JNK inhibitor SP600125, we revealed that PGE1 blocked HG-triggered activation of JNK/Bim pathway in HK-2 cells; JNK was an upstream regulator of Bim. In conclusion, our results demonstrate that the nephroprotective effects of PGE1 against apoptosis of proximal renal tubule in DKD rats via suppressing JNK-related Bim signaling pathway.
Assuntos
Alprostadil/farmacologia , Apoptose/efeitos dos fármacos , Nefropatias Diabéticas/tratamento farmacológico , Glucose/antagonistas & inibidores , Túbulos Renais Proximais/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Alprostadil/administração & dosagem , Animais , Proteína 11 Semelhante a Bcl-2/antagonistas & inibidores , Proteína 11 Semelhante a Bcl-2/metabolismo , Células Cultivadas , Nefropatias Diabéticas/induzido quimicamente , Nefropatias Diabéticas/patologia , Glucose/farmacologia , Humanos , Injeções Intravenosas , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Túbulos Renais Proximais/metabolismo , Túbulos Renais Proximais/patologia , Masculino , Substâncias Protetoras/administração & dosagem , Ratos , Ratos Wistar , EstreptozocinaRESUMO
Diabetic nephropathy (DN) is one of the serious complications of diabetes mellitus. Orientin, a major bioactive constituent of Fenugreek, has been reported to possess antihyperglycemic properties. However, its effects on DN remain unclear. Therefore, we explored the protective effect of orientin on podocytes. Here, we assessed cell viability and toxicity, level of autophagy, mitochondrial morphological changes, and podocyte apoptosis. The results indicated that high glucose (HG) induced podocyte apoptosis as well as mitochondrial injury can be partially blocked by orientin. The results showed that orientin could repair autophagy disorder induced by HG, while 3-methyladenine (3-MA) reversed the protection of orientin. Our study demonstrated the possibility of treating DN with orientin.
Assuntos
Apoptose/efeitos dos fármacos , Flavonoides/farmacologia , Glucose/antagonistas & inibidores , Glucosídeos/farmacologia , Podócitos/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Flavonoides/química , Glucose/farmacologia , Glucosídeos/química , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Conformação Molecular , Podócitos/metabolismo , Substâncias Protetoras/químicaRESUMO
The dipeptidyl peptidase 4 inhibitor vildagliptin (VLD), a widely used anti-diabetic drug, exerts favourable effects on vascular endothelium in diabetes. We determined for the first time the improving effects of VLD on mitochondrial dysfunction in diabetic mice and human umbilical vein endothelial cells (HUVECs) cultured under hyperglycaemic conditions, and further explored the mechanism behind the anti-diabetic activity. Mitochondrial ROS (mtROS) production was detected by fluorescent microscope and flow cytometry. Mitochondrial DNA damage and ATP synthesis were analysed by real time PCR and ATPlite assay, respectively. Mitochondrial network stained with MitoTracker Red to identify mitochondrial fragmentation was visualized under confocal microscopy. The expression levels of dynamin-related proteins (Drp1 and Fis1) were determined by immunoblotting. We found that VLD significantly reduced mtROS production and mitochondrial DNA damage, but enhanced ATP synthesis in endothelium under diabetic conditions. Moreover, VLD reduced the expression of Drp1 and Fis1, blocked Drp1 translocation into mitochondria, and blunted mitochondrial fragmentation induced by hyperglycaemia. As a result, mitochondrial dysfunction was alleviated and mitochondrial morphology was restored by VLD. Additionally, VLD promoted the phosphorylation of AMPK and its target acetyl-CoA carboxylase in the setting of high glucose, and AMPK activation led to a decreased expression and activation of Drp1. In conclusion, VLD improves endothelial mitochondrial dysfunction in diabetes, possibly through inhibiting Drp1-mediated mitochondrial fission in an AMPK-dependent manner.